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(N0 ModeL) A. unone Ass.

OPERATING COMPRESSED AIR APPARATUS.

No. 315,013. I Patented Apr. 7, 1885.

JJVVENIOR A? .dttorney..

N. PETEns. M VIM a C.

UNITED STATES PATENT OFFICE.

ANTHONY O. DOUGLASS, OF \VASHINGTON, DISTRICT OF COLUMBIA.

OPERATING COMPRESSED-AIR APPARATUS.

SPECIFICATION forming part of Letters Patent No. 315,013, dated April 7,1885.

Application filed Decembcrf), 1884. (No model.)

To aZZ whom it may concern.-

Be it known that I, ANTHONY 0. Done- LAss, a citizen of the UnitedStates of America, residing at Washington, in the District of Columbia,have invented certain new and useful Improvements in OperatingGoinpressed-Air Apparatus, of which the following is a specification,reference being had therein to the accompanying drawing.

This invention relates to an improvement in compressed-air apparatus;and it consists in a method of separating from the air the Water whichis usually incorporated with it in the process of compression.

When air is being compressed, the process of compression generates agreat amount of heat, and thus the cylinders and pistons of thecompressors become so much heated as to prevent the working of the sameat any reasonably fast speed. To overcome this diiflculty it has beenthe practice to force into the cylinder of the compressor at each strokecold water, preferably and generally in the form of spray, to keep thecylinder and piston cool, and thus the compressor could be worked at areasonably fast speed, say from sixty to eighty strokes per minute; butanother trouble arose. The water thus sprayed into the cylinder becameincorporated with the air, and

the combined water and air passed off to gether to the compressed-airreservoirs,wh ere it has been the custom to discharge the mixed air andwater below, and through water contained in the bottom of saidreservoirs. The water, however, in the reservoirsoon becomes hot fromthe continued increment of the heat in the air, and hence the fine sprayor vapor mingled with the air is not condensed in the water, but passesinto the pipes with the air, and from thence goes to the engine, thusfrequently stopping the work until the water has been removed or haspassed away. This is a great difficulty in cold weather, for itfrequently happens that the air has to be conveyed a long distance inthe pipes before it reaches the engine, and thus frequently the watersettles in the bends of the pipes or low places and becomes frozen,or ifnot frozen lessens the capacity of the pipes by the amount of thecontained water, and thus the pressure of the air is lessened and theduty of the compressors increased. Attempts have been made to overcomethis by surrounding the cylinder of the compressor with a waterj acket,instead of injecting water into the cylinder. This, however, isobjectionable, as it does not affect the piston, which becomes highlyheated by the generated heat, and hence the packing and lubricant becomeburned from the combined heat and friction, and the compressors thusmade necessarily have to be run very slowly compared with that class ofcompressors wherein the coolingwater is forced into the inside of thecylinder,v and thus, although water,- jacketed compressors .arepartially successful for some purposes, they cannot begin to competewith those in which the water is injected into actual contact with thepiston and the inside of the cylinder, and the latter class ofcompressors are therefore almost invariably used, notwithstanding thedifficulty of the water carried over by the air, heretofore referred to.To overcome this difficulty I propose to keep the water into which thecompressed air is discharged always cool by continually forcing'a freshsupply of water into the vessels containing the coolingwater, andallowing the heated water to pass away, as hereinafter described.

The accompanying drawing represents a side view of the apparatus Iemploy in carrying out my invention, partlyin vertical section.

A shows an air-compressor of any suitable form, and operated in anyknown manner.

A represents one of the coolers, into which enters the pipe B, connectedwith the air-compressor and terminating belowthe level of the watercontained in said cooler, and near the top of said cooler A is a pipe,0, which passes into another cooler, D, and terminates below the levelof the waterin said cooler D, p

which cooler is provided with a pipe, E, near its top to carry the airto the air-drill M, or other machinery to be driven by the compressedair.

At F is shown a pump connected directly with the air-compressor, andused to force a jet of cold water into each end of the cylinderalternately, in the usual manner for cooling the cylinder, piston, &c.Connected with each end of the discharge of the pump F is a pipe, H,through which a constant supply of cold water from said pump F is forcedinto the coolers A. D, so that the water in said 0001- I would ers isalways cold.

At I is shown a pipe connecting the two coolers, by which an equal levelis maintained in both, and at J is shown a cock by which the water canbe withdrawn as it becomes too high.

I have shown three ways of discharging the water from the pump into thecoolers A D, either of which, or others, maybe employed at the will ofthe constructor of the apparatus, In the first of these the water isdischarged in a solid stream into the side of the cooler A by the branchpipe h. In the second form shown the water is carried up into theinterior of that part of the air-pipe B contained within the cooler A.by a perforated pipe, K, through which the water is discharged in aseries of jets, whereby the incoming air is subjected to jets of coldwater before it enters the main body of the water in the cooler. In thethird form shown the incoming water is discharged through a rose, L,directly beneath the incoming air, as in the cooler D.

The coolers A D should be provided with glass gages, so that the heightof the water may be known and regulated by the cock J.

By this method of operation, all the water, or substantially all, iseliminated from the air, and thus a great hinderance to the work of theengine is avoided.

I deem it important that the air passes freely through the water, andthat there be nothing contained in the same that will hinder such freepassage, because if the air does not have such free passage more powerwill be necessary to drive the air through, and the pressure availablefor driving the air-engine will be lessened.

1 also deem it important that the incoming water enters the body ofwater at a low point therein, and that the heated water be withdrawn ata high point, because the water at the highest point is the hottest.

I am aware that it has been proposed in icemaking machines to moistenair before it has beencompressed, and then after compression to cool thesame by first forcing it through porous matter over which water wascontinually sprinkled, and then drying the air thus cooled by forcing itthrough other porous matter kept at a comparatively dry state, as shownin the Patent No. 112,726; but this mode, although it may act withconsiderable success in an icemaking apparatus, would be a'failure inworking air'engines, owing to the loss of power caused by forcing theair through the porous material. Moreover, the said porous material actas a filter, and by gradually separating the solid matter from the waterpassing through become in time such a solid mass as to make it almostimpossible to force the air through without too great an expenditure ofpower to make it .pay to use air cooled in this manner to driveair-engines. These modes of drying air are essentially different frommine, in which the air is cooled andthe spray separated from the same bythe actual contact with a body of water kept at a substantiallyuniformly-cold temperature by the continual injection of cold water,through which body of water the intermingled air and water freely passeswithout losing its power by being forced through the pores of solidmaterials.

What I claim as new is-- 1. The improvement in operating compressed-airapparatus, which consists in first compressing air in pumps kept cool byforcing water into the interior of the pump-cylinder, and then passingthe mixed air and spray through a body of free water kept at asubstantially uniformly-cold temperature by the injection of fresh coldwater and the withdrawal of the water heated by the air, substantiallyas and for the purpose specified.

2. The improvement in operating coinpressedair apparatus, which consistsin first compressing the air in pumps kept cool by forcing jets of waterinto the interior of the pump-cylinder, and then passing the mixed airand spray through a body of free water kept at a substantiallyuniformly-cold temperature by the injection of cold water at a low pointin said water and the withdrawal at a high point of the water heated bythe air, substantially as andfor the purpose specified.

3. The improvement in operating compressed-air apparatus, which consistsin first compressing the air in pumps kept cool by forcing water intothe pump, then subjecting the mixed air and spray to jets of cold water,and then passing the same through a body of free water kept at asubstantially uniformlycold temperature by the admission therein at alow point of said jets of cold water and the withdrawal at a high pointof the heated water, substantially as and for the purpose specified.

In testimony whereof I affix my signature, in presence of two witnesses,this 9th day of December, 1884.

ANTHONY O. DOUGLASS.

W'itnesses:

T. J. W. RoBnRTsoN, M. P. CALLAN.

